Balanced piston-valve for compound engines



(No Modem zsneets-sneet 1.

H. lCANPIELDl BALANGBD PISTO-N VALVE FOB. GOMPOUND ENGINES.

(No Model.) 2 sheets-Sheen 2.

H. CANFIELD. BALANGED PISTON vVALVE POR GOMPOUND ENGINES. No, 477,924.

Patented June 28, 1892.

WITNESSES. Piz? nm Evans ca. Fumo-mnu, wAsmNsTaN UNITED STATES .PATENT OFFICE.

HOBART CANFIELD, on MoRRisTownNEw JERSEY.

BALANCED PlSTON-VALVE FOR COMPOUND ENGINES.

SPECIFICATION forming part of Letters Application filed April 23, 1891.

Toa/,ZZ whom, t may concern.

Be it known that I, HOBART CANFIELD, of Morristown, in the county of Morris and State` of New Jersey, have invented a certain new and useful Improvement in Balanced Piston-v Valves for Compound Engines, of which the following is a specification.

This invention relates to balanced valves of the piston class employed in compound marinelocomotives and stationary engines; and it consists of a single piston-valve governing the admission and exhaust of steam from both the cylinders, the said valve having a reduced end, whereby the valve is balanced,and reciprocating in a steam-chest casing open at both its ends.

- In the accompanying drawings, Figure l is a longitudinal section of a cylinder steamchest and valve embodying my improvement. Fig. 2 is a transverse section through the line of Fig. 1. Fig. 3 is a transverse scction through the line'y'y of Fig. l. Fig. 4 is a side View of the valve. Fig. 5 is a section through either of the lines z 5 of Fig'. 4, and Fig. 6 is a section through either of the lines z z of Fig. 4.

Referring by letter to the drawings, A designates the high-pressure cylinder, and A is the low-pressure cylinder, on the same center line with the first-named cylinder. Y The cylinder A is provided with a piston A2 andthe cylinder A has the piston A3. These pistons are connected together in the usual manner and may be provided with the usual packingrings a.

B designates the piston-valve, consisting, essentially, of the hollow cylinder b and they piston-heads B', which are here shown as seven in number, although a greater or less number may be used without departing from the spirit of my invention. The head B at one end of the valve is of smaller diameter than the other heads, and the cylindric portion of the valve between said end head and the next adjacent head is of less diameter than the cylindric portion between the other heads. By this construction the entering steam has an increase of pressure on the second head over that of the Iirstor reduced head,

whereby the valve lis perfectly balanced in Patent No. 477,924, dated June 2s, 1892.. serif-.1 No. 390,077. (No moar-.1.)

its operation. Each of the piston-heads B may be-provided with annular channels, into which metal packing-rings b are fitted and properly doweled to break joints. Port-openings b2 extend through the cylinder b between 'certain of the heads B. The openings b2 for the passage of live steam are shown as largerv than the otheropenings b2. Closures or heads b3 b4 are provided at the respective ends of the cylinder b. From the closure b3 a valverod a. extends to connectwith any well-known driving mechanism, whereby a'reciprocating movement is imparted to theV piston-valve.

C designates the steam-chest, into which steam may be admitted through the opening or openings c. As shown inthe drawings, the steam-chest C is located opposite the highpressure cylinder A.

D D D2 D3 designate steam ways or ports providing for the entrance of steam to the high-pressure cylinder and for the exhaust therefrom to the low-pressure cylinder. The liner E is also provided with ports communieating with the ports D D D2 D3.

`0f course in this construction of Valve there is no pressure ofgsteam on the ends thereof. In the drawing Fig. 1 it will be seen that the pistons A2 A2 are about to be moved in the direction indicated by the arrow adjacent to the piston A2, and the various arrows showthe course of the steam and exhaust. Forinstance, steam is admitted tothe high-pressure cylinder throughv the port D, the exhaust passes from the high-pressure cylinder through the port D to the interior of the valve by way of ports b2 and through the port D2 into the low-pressure cylinder, and the exhaust from the low-pressure cylin- Yder escapes through the port D3 to an exhaustoutlet E. Of course when the direction of the valve movement is reversed the live steam is admitted to the high-pressure cylinder through the port D and the exhaust is through the port D into the low-pressure cylinder through the port D3, the exhaust thereupon being through the port D2.

Having described my invention, what I claim is In a balanced valve, the combination of a steam-chest, a valve-casing open to the atmosroc In testimony whereof I have signed my naine toA this specification in the presence of two subscribing witnesses.

HOB ART CANFIELD.

Vitnesses:

C. R. FERGUSON, S. O. EDMoNDs. 

